The combination of microelectronic circuits and low power liquid crystal displays (LCD displays) has led to a wide variety of portable electronic products. These products range from electronic watches to hand-held television receivers and lap top computers. Low power consumption is a critical requirement for each of them.
Despite their considerable utility in conjunction with integrated circuits, LCD displays have a number of shortcomings. In typical LCD cells the activated portion is darkened, representing a visual message, and the unactivated portion is transparent, constituting visual background. One shortcoming of LCD displays is the relatively low contrast between the activated portion and the unactivated portion. The contrast can be increased by backlighting the cell, thereby producing a sharp visual contrast between the portions of the cell darkened by activation and the light shining through the transparent regions. Unfortunately, conventional backlighting arrangements are inefficient. Even in so complex an electronic structure as a portable computer, the power used in display backlighting is the major drain on the system batteries.
The copending application Ser. No. 07/816405 discloses a microtextured reflector having dispersion characteristics of enhanced uniformity and a display device which can be read over an enhanced range of viewing angles. Specifically, a reflector comprises a base plane having a microtextured surface comprising a pattern of microelements having maximum lateral dimensions less than 125 micrometers and smooth continuous mold-formed surfaces arising from the base plane. A preferred reflecting surface is composed of closely packed, smooth-surfaced spherical segments having diameters of twenty-five microns and attitudes of four microns.